the usb-uirt that Sheesh mention (http://www.usbuirt.com) also has an 1/8" emitter out port on it that you should be able to use to drive the Xantech connecting blocks like this one [Link: xantech.com] that will drive up to 20 emiiters (if using xantech's dual emitters).
You might have power issues though (i'm not sure how much output the USB-UIRT has) so you might need the [Link: xantech.com] which is an amplifed connecting block. Oh, and the power supply to run it (Xantech 781RG).